Check whether you can choose, compare the compulsory household cost and leave with a reasoned recommendation and next steps.
The deadline and your current status matter before the costs do.
LAMal and the French health-insurance system are not two interchangeable policies. They are two legal routes with different contribution logic, access rules and administration. The useful comparison begins with whether you can choose at all, then models the people who would actually be attached to each route.
A France resident beginning Swiss employment normally has three months to choose between Swiss compulsory insurance, LAMal, and affiliation through the French system. A new window can also arise after resuming Swiss work following French unemployment or activity elsewhere, moving to France while remaining Swiss-employed, or changing from worker to Swiss pensioner. Workacross projects the date three calendar months forward, but the canton decides the legally effective received-by date.
Ordinary changes do not generally restart the clock. Marriage, divorce, a birth or death, changing Swiss employer without a break and telework by itself are not new option events. Once a valid choice has been made, or the window has passed, the decision is normally binding while the underlying status remains. Missing the window can lead to compulsory LAMal affiliation and consequences for late enrolment, so confirm an urgent or disputed deadline directly with the canton authority.
For 2026, the modeled French contribution is 8% of the positive difference between an individual frontier worker's 2024 CNFTS or Urssaf income and EUR 12,015. That EUR 12,015 is 25% of the 2026 annual French social-security ceiling. The base and contribution are rounded for an annual estimate, and an entry or exit during the year is prorated by covered days.
This is not an automatic copy of the household revenu fiscal de référence. The CNFTS declaration starts with the individual frontier worker and applies the published income rules. If two adults are Swiss frontier workers, each receives their own abatement and contribution calculation. The two-year lag also matters: a 2026 contribution reflects 2024 income, so a salary change affects the French side later than it affects your present budget.
LAMal charges an official France-resident premium for every person attached to the Swiss choice: adults, young adults and children are distinct bands, with any published third-and-following-child tier applied by insurer. An inactive partner and children may therefore add several individual premiums. Under the French route, eligible dependants do not simply create a second percentage contribution in the same way.
Family coordination is legal before it is financial. A partner working in France is normally insured through that French activity; another Swiss frontier worker needs an individual option and contribution; and children must be attributed once under the coordination rules. When that attachment is unclear, the assistant gives a range and stops at authority review instead of pretending the more convenient household model is settled.
With LAMal, the insurer issues an S1 form for registration with CPAM, allowing care in France under French rules while Swiss care remains part of the Swiss compulsory route. In France, a European Health Insurance Card is used for temporary care elsewhere in the EU or EFTA. Swiss cost sharing still applies to care billed under Swiss rules, including the applicable deductible, co-insurance and hospital contribution.
With French affiliation, routine care is naturally centred in France. Access to planned care in Switzerland can depend on coordination and prior authorisation, including an S2 in situations where that procedure applies; a European card is for medically necessary care during a temporary stay, not a blanket substitute for planned treatment. If dependable planned Swiss treatment is essential, the assistant can recommend LAMal even when it costs more and states that extra cost openly.
This France-resident launch deliberately covers the six highest-volume workplace corridors in the official 2025 Q4 frontier-employment data: Geneva, Vaud, Basel-Stadt, Neuchâtel, Basel-Landschaft and Jura. It does not present every canton as equally relevant. The underlying registry remains extensible, including a separate six-corridor set for Germany, while an out-of-corridor case should be confirmed with the authority rather than forced through this model.
The official LAMal premiums used here are the 2026 amounts for people resident in France. They are country-of-residence premiums, so changing the Swiss workplace canton does not by itself change the premium. Insurer, age band, accident inclusion and the people attached to the policy do. Before enrolling, use the insurer comparison as the second stage and confirm the real quote.
The decisive path supports the standard EU or Swiss national with one Swiss employment. EFTA or UK status, third-country nationality, posting, self-employment, combinations of work and pensions, employment in another country, uncertain A1 status and material multi-state telework can change which social-security law applies before LAMal versus the French route is even considered.
A manual-review result is useful: it preserves the modeled cost range and tells you exactly what needs confirming without turning an assumption into legal advice. Contact the canton authority, CPAM or CLEISS with the work pattern, nationality, household attachment and relevant dates. Costs here are estimates, not insurer quotes or binding affiliation decisions.
The questions most likely to change what you do next.
It is normally binding while the underlying situation remains the same. A genuinely new status event can reopen the option, but marriage, divorce, a birth or death, an ordinary employer change without a work break and telework alone generally do not. Ask the canton authority if your event is disputed.
The likely outcome is compulsory Swiss LAMal affiliation, potentially with late-affiliation consequences. The assistant shows a projected date, not a legal filing receipt; confirm the exact received-by deadline with the competent canton, especially when only days remain.
Usually not on its own. An employer change without an interruption, marriage, divorce, birth or death normally does not reopen the right of option. A real change of status such as resuming Swiss work after French unemployment may do so.
Some cross-border and necessary care is coordinated, but planned substantial treatment in Switzerland can require prior authorisation and the applicable S2 process. A European Health Insurance Card is for necessary care during a temporary stay, not unrestricted planned Swiss treatment.
That depends on the parents' activities and the family coordination rules. Children must be attributed once. When one partner works in France, both are frontier workers, or the attachment has not been confirmed, use the displayed range and ask CPAM or the canton authority to validate it.
An employee working at least eight hours per week for the same Swiss employer is generally covered by that employer for non-occupational accidents, so the health premium without accident normally applies. Confirm the actual cover with payroll; leave it uncertain in the tool if you cannot.
The published CNFTS process uses an N−2 income reference. That delay means a raise or reduction today does not immediately appear in the French contribution. The scenarios show the eventual direction while keeping the 2026 full-year estimate tied to 2024.
The premiums modeled here are the official 2026 rates for insured people resident in France. The canton changes which office handles the option and its instructions; insurer, age, accident cover and household attachment change the premium.
Check whether you can choose, compare household costs and leave with a sequenced action plan.